in this paper, the flow around bluff bodies with different cross sections and determination of forces acts on them are investigated.this paper presents the results of a numerical study on the flow characteristics and heat transfer over two equal square cylinders in a tandem arrangement. spacing between the cylinders is 5 widths of the cylinder and the reynolds number ranges from 1 to 200, pr=0....

Background During rapid filling of the left ventricle, a vortex ring forms downstream from the mitral valve. Previous experiments in water tanks have shown that vortex ring formation is an optimized method for fluid transport. The rotation of the vortex ring leads to mixing of the inflowing blood and blood that was already in the ventricle (Figure 1). In water tanks, the amount of mixing decrea...

For moderate Reynolds numbers, a sphere striking a wall in the normal direction leads to the trailing recirculating wake threading over the sphere and developing into a complex vortex ring system as it interacts with the wall. The primary vortex ring, which consists of vorticity from the wake, persists and convects slowly outwards away from the sphere due to the motion induced from its image. T...

We show that zero-energy flows appear in many particle systems as same as in single particle cases in 2-dimensions. Vortex patterns constructed from the zeroenergy flows can be investigated in terms of the eigenstates in conjugate spaces of Gel’fand triplets. Stable patterns are written by the superposition of zero-energy eigenstates. On the other hand vortex creations and annihilations are des...

Dynamics of vortex pairs with the same and opposite circulations are studied theoretically in nonlocal nonlinear media with different intervortex separations. We demonstrate that the nonlocal nonlinear response not only leads to a dramatic suppression of the elliptical instabilities but also helps in the formation of quasi-stable rotating and breathing bound states for vortex–vortex and vortex–...

Rankine vortex characteristics of a partially coherent optical vortex are explored using classical and physical optics. Unlike a perfectly coherent vortex mode, the circulation is not quantized. Excess circulation is predicted owing to the wave nature of composite vortex fields. Based on these findings, we propose a vortex stellar interferometer.

2 9 Repetition of the male back-cross test with star dichaete ......................... 290 Location of the vortex genes through linkage tests with star and dichaete.. ..... 292 The localization of vortex I1 by aid of streak .................................. 296 The streak vortex modifier 300 Further tests of the position of vortex I11 301 The isolation of an (additional vortex intensifier.. 3...

Model equations for describing and efficiently computing the radiation profiles of tightly spherically focused higher-order electromagnetic beams of vortex nature are derived stemming from a vectorial analysis with the complex-source-point method. This solution, termed as a high-order quasi-Gaussian (qG) vortex beam, exactly satisfies the vector Helmholtz and Maxwell's equations. It is characte...

Concentrated suspensions of swimming microorganisms and other forms of active matter are known to display complex, self-organized spatiotemporal patterns on scales that are large compared with those of the individual motile units. Despite intensive experimental and theoretical study, it has remained unclear the extent to which the hydrodynamic flows generated by swimming cells, rather than pure...

Vortex dynamics in coherent ensembles of exciton polaritons (condensates) is studied in the framework of the polarization-dependent Gross-Pitaevskii equation. Vortex lattices can be resonantly excited in the polariton field by the interference of three or more optical pumps. Vortex-antivortex pairs can also appear in polariton condensates due to scattering with disorder. The nonlinear vortex dy...